Locking device for semitrailers



D88. 29, 1931. F; M. man:A 1,888,868-

' LOCKING DEVICE FOR' SEMITRAI'LERS- ATTORNEY.

Dec. 29, 1931. F. M. REID l LOCKING DEVICE FOR SEMITRAILERS Filed July 9. 1926 3 Sheets-Sheet 2 INVENTOR. Muck k/cabme/'QZ BY` www Dec. 29, 1931; F. M. REID 1,838,868

LOCKING DEVICE FOB SEMIIRILILERS Filed July 9. 1926 3 SheetsuSheet 5 T Tr- L- s [I ;TL- I F- v l @fw v INVENTOR.

KA ORNEY.y

60 the semi-trailer. j

lPatented Dec. 1931 y UNITED STATES PATENT OFFICE FREDERICK MALCOIJM REID, or DETRoIr, MICHIGAN, AssrGNoR mo FRUEHAUI TRAILER COMPANY, or DETROIT, MICHIGAN, A CoRroRA'rIoN or MICHIGAN LoCxING'DEvICE FOR sEMITRA'ILnRs Application led July 9.1926. Serial No. 121,287: A

This inventionrelates to semi-trailers and hasto do more particularly with a locking device for locking a `semi-trailer to a vehicle for drawin the same. 5 Semi-traders are constructed with lwheels for supporting-the rear end, and the forward end is supported vby alvehicle su'ch as a tractor. 'For this purpose the semi-trailer is usually provided with an upper fifthwheel construc- 10 tion, and the tractor with a lower fifth wheel constructionfl The tractor is detachable from the semi-trailer and there is usually a support for holding up the front end of the semitrailer, this support being moved out of the 16 way when the ltractor and semi-trailer are connected. Various locking devices have been devised for locking the semi-trailer and tractor together, and itv has been .proposed to so construct the locl and the support, and

20 connect the two,.so'that the support is moved i the tractor backs into the semi-trailer, and. 80 many times there is a severe j ammln action.

It is desirable that the lock construction be such as to eliminate, as far as possible, breakage thereof and, furthermore, it is desirable to have a lock where a ositive operation is' assured so that faulty ocking, which may According to the present invention the ,lock is constructed so as tolbe operative to engage and disenga e the tractor -by a reciprocable movement w ich is 'caused by the movementl of the tractor itself. The device is generally in the form of a clam lock; that is, it has twomovable members working in conjunction with each other to a co-operating member on the tractor. e action on the two members is positive, thus insuring 4against faulty locking. The reciprocable vmovement of the'lock is'utilized to do work as, for instance, operating the support-of result in an accident, is guarded against.

. ceive the king-pin.

In theaccompanying drawings, Fig. 1 is a plan view of part of the trailer frame showing. the lock `and the supporting structure; Fig. 2 is a side elevation showing the semi- Y trailer secured to a tractor; Fig. 3 is an en- 55 larged detail of the lo'clng mechanism; and Fig. 4 is a section taken on line 4 4 of Fig. 3.

Referring to the drawings and particularly to Figs. land 2, the trailer includes a frame or platform 1, the rearend of which e is supported by wheels.. (not shown). The forward end of the trailer frame is supported by a tractor 2.through a fifth wheel con struction 3.' The fifth Wheel of the tractor carries a king-pin 5 which is adapted to be e5 engaged by the lo'cking device carried b the semi-trailer frame. The front end o theframe is provided with bumper-like members 6r providing an open passageway 7'. These `bumper-li e members ride over the 'lo lower fifth wheel construction of the tractor when it backs into the semi-trailer, and the king-pinA enters the passageway 7.

Thelo'cking device includes a reciprocating head 10 which carries, pivotally, a pair 75 of lock members 11 and 12.l This reciprocating head andthe two lock members reciprocate inundercut slideways. This is provided by plates 13 and 14 upon which are bolted or riveted brackets 15 and 16. Secured to so the to of the brackets are plates 17 and 18, thus orming a pair of undercut'slideways (see Fig. 4). As indcatedin Fig. 3, each slideway turns outwardly as at 20 and 21.

The two members of the lock are provided 85 with bill-like members 22 whichY engage around the kingin 5T T he forward portions of the bill-li e members are shaped so as to form slanting side walls in orderto insure that the king-pinv will enter between the two locking membersl in a proper manner.

The two members are normallyypressed"out- .i

wardly by means of a coil spring 25. A

As lndicated in Fig. 1,.. the lock is in open position. In this'position the lreciprocatmg 915 head is forward-,and the two lockm members project beyond the end of the sli eways. The coil spring causes the two members of the'clam lock to open in a position to reen a tractor backs into the trailer the king-pin enters the passageway 7 and strikes a projection 26 of one of the locking members. Further backward movement of the tractor pushes the clam lock back and the king-pin passes through the channel 27 which lles between the two plates 13 and 14. The two locking members are swung upon their pivots and engage the king-pin, as indicated in F ig. 3.

In order to hold the clam lock in this locking position a latch 30 is rovided. This latch is carried on the end o a rod 31 and is normally pressed into locked position by means of a coil spring 32. In order that an operator may release the latch, the end of the rod 32 is connected to a bell crank 33, pivoted as at 34, which is connected to, and is operable by means of, a handle 35. This general description of the latch is belived to be suilicient in so far as it relates to the locking device. This latch includes other mechanism by which certain operations are automatic,`

but this forms the subject matter oa separate application wherein such construction is fully described.

The entire locking mechanism is made up as a unit which can be easily inserted in place and bolted tothe frame pieces of the trailer. The two plates 13 and 14 are assembled toether by neans of an le irons 40 and 41.

shown at 42 and 43. The clam lock, and the slides, are mounted on the plates and thus the locking structure is formed as a unit. The operation of mounting the locking structure on the trailer frame is thus simplified. It is only necessar to put the unit into place, and

Y' the four ang e irons are then bolted to the members of the frame as shown at 45. The locking unit is bolted to the forward cross member of the frame 46, the cross member 47 and to lo itudinally extending members 48 and 49. e channel of the member 46 faces inwardly, and it is cut away as at 46 to permit the lock to be put in place. After the lock has been put into place, the latch 30 may be easily connected to the lock through holes provided for that purpose. The connection may be made by screw threads. Also, a rod 5 0 is connected to the reciprocating lock member, after the lock is inserted in place.

This also may be done by merely screwin the rod into a socket provided in the hea for that purpose. It will thus be seen that the assemblying operation is simplified as the lock construction is mounted in the trailer frame as a unit, and that only two separate connections need be made.

As indicated in Figs. 1 and 2, the rod 50 extends toward the rear end of the trailer. This rod reciprocates with the reciprocating clam lock, and operates to raise and lower the supporting wheels 51. These supporting -wheels are carried by frame 52, the ends of the frame being slidable in the inclined slideach plate has at its, e ge an angle iron as.

1,sse,sea

way 53, and vthe longitudinal slideway 54. The frame is connected by rods to the rod 50, as shown at 56. It will be understood that when the lock is engaged with the .kingpin of the tractor the supporting Wheels and frame are in raised osition as shown in Fig. 2, and that when t e tractor\is.disengaged from the truck, the support moves down and the wheels 51 engage with the ground for supporting the forward end of the trailer.

The trailer ma also include mechanism for operating brakes on its wheels, and this mechanism may operate through a fifth wheel construction. For this purpose the king-pin has a plunger extending therethrough and which is operable by means of thev rod 61 which leads to the drlvers seat. The plun er moves up and down and actuates a mem er 62 which is secured to a rock shaft 63 and which is in turn connected to the wheels of the semi-trailer by means of a rod 64.

It will be observed that a lock constructed in accordance with this invention, is made up as a unit and easily and quickly mounted in the trailer frame, and that only two connections need be made after the unitary lock construction is so mounted. The arrangement of the clam lock provides for positive locking and unlocking operation. As the tracu tor backs into the trailer the clam lock is pushed rearwardly. This movement causes the two members of the clam lock to move toward each other, thus engaging lthe kingpin. At the end of the rearward movementthe latch springs into place and the connection is completed. During the rearward movement of the clam lock the su porting frame of the semi-trailer is lifted rom the ground. In the releasing operation the drivf er retracts the latch 30 by means of the handle 35. The tractor is now moved forwardand the clam lock is pulled forward. This action pulls the rod 50 forward and lowers the supporting frame with a positive action. When vthe claim lock reaches the end of the undercut slideways the two members se a.,- rate and thetractor becomes disconnecte I claim:

1. In a combined vehicle of the character described comprising a tractor and a trailer, a coupling mechanism comprising, in combi nation, a vertical king pin on the tractor, a pair of horizontally swingable jaws mounted on the trailerand providingv a forwardly opening coupling socket for receivingA said king pin, means for causing said jaws to be closed about said king pin including a head ,operatively connected to the jaws and adapted to be reciprccated back and forth on the trailer as the tractor moves toward and away fromthe trailer during coupling and uncoupling and in such actuation to closel and open said jaws, and a member operable to lock said head in itsrearward or coupled position s'o that the tractive force ofthe tractor may be 1,sss,aee

applied to the trailer through the medium of said 'aws and-,said head. i 1

2. a semitrailer and tractor combination with a kngin on the tractor, an u per fifth wheel mem r having a longitu al forwardly diverging lslot for the king-pin of the tractor, a pair of guide members su l ported above and one on each'side of said slot, and one or more kin -pin-engaging jaws sup rted in and' 'de and held closed by sal guides when t e jaw or jaws are pushed rearwardly, and means for holding-the jaws in their rearmost position locked about the king-pin, and a service bar for performing one or more service operations on the trailer movable with said jaws by theV actuation of the kingpin.

4. In a semitrailer and tractor combination with. a kingfpin on the tractor, an u per fifth i wheel member having a longitu inal forwardly diverging slot r the king-pin of the tractor, a pair of guide members supported above and one on each side of said slot, and one or more kin -pin-engaging jaws supported in and gui ed and held closed by said guides when the jaw or jaws are pushed l rearwardly, and a latch in one of the guide members arranged to automatically engage and hold one of the members moving between said ide members.

5. a trailer-tractor combination-of the arranged to engage behind one o being effected by their enga ement with the guide members, anda latc in one of the guide members arranged to automatically engage and hold one of the members lmoving,

between said ide members.

7. In a traller-tractor combination of the semitrailer type, a slotted up er lifth wheel member V,arranged to receive and guide a king-pin, a pair of angle armguides along said slot and secured to the plate, and one or more jaws slidable alongsaid guides to engage and hold the king-pin, a .releasable latch passing through one of the guides and the jaws.

8. In a trailer-tractor combination of the semitrailer type, a slotted upper fifth Wheel member arranged to receive and guide a king-pin, a pair of angle arm guides along said slot and secured to the plate, and one or more jaws slidable alon said uides to engage and hold the king p1n, a re easable latch passing throughA one of the guides and arranged' to enga e behind one of the jaws, and a service bar or performing one or more service operations on the trailer movable' with said jaws 'by the'actuation of the king- 1n. .p In testimony whereof I aiix my signature.

FREDERICK MALCOLM REID.

automatic semitrailer type, the combination of a tractor provided with an u standing king-pin, a trailer having a slotte plate on the under side fixed in a stationary relationv therewith, guides su ported by said plate, one or more Jaws gui ed between said guides when the king-pin enters said slot in the plate and serving to enatg the king-pin when the jaws pass towar e rear of said guides,

and a latch in one of the guide members arv ranged to automatically engage and hold, one of the members 'moving between said guide members.

jaws arranged to slide between the 6. In a semitrailer-tractor combination, a tractor Aprovided with a king-pin, a trailer having a pair of lixed longitudlnally extending guides having at the front one or more dlvergmg cam surfaces, one or more cm and be cammed into engagement wit the hilf-pin' whenthe king-pin strikes the same .fan pushes themv back, the camming action 

